In the original parent patent application by the same authors, for which this is a continuation-in-part patent application, apparatus and method were described which included high frequency electrodes that are to be connected to a high frequency power source to heat bodily tissue when the electrode is inserted into the tissue, in conjugation with a cooling system which enables cooling of the electrode and the tissue just adjacent to the electrode so as to modify the thermal distribution of heat deposition in the tissue. Also described in the parent application were methods and apparatus for ablation of cancerous tumors by insertion of stiff electrodes into the body and creating an appropriately controlled lesion to engulf the tumor. Various configurations of electrodes and active, inactive, and boundary condition electrodes were shown for various geometric configurations in the body. Description of a complete control system integrated for controlling the temperature and power and other parameters associated with the heating and the cooling system were described, and the integration with the electrode system and patient related applicators with thermal sensing was detailed.
In the present continuation-in-part, we describe further designs of cooled-tip, high frequency electrodes well suited for percutaneous minimal invasive ablation of tumors or other structures within the tissue of the body. Specific apparatus embodiments are described that would be utilitarian in the thermo-surgical setting and which have physical characteristics to improve control and practical handling. Particular assemblies of cannulae, fluid cooling, irrigating and perfusion devices, radiofrequency cannulae, and thermal probes are given which make it possible to construct such a practical thermo-surgical applicator while preserving the integrity of control measurements, proper fluid seal joints, proper cleaning and flushing characteristics.
Further objectives of the present continuation-in-part is to describe cooled tip high frequency ablation electrode systems that are advantageous for ablation of cancerous tumors by percutaneous or intraoperative sticking of the electrode through the patient""s skin or tissue so as to achieve the site of the tumor volume and practically ablate it.
Yet another objective of the present continuation-in-part is to show practical ways of constructing a thermo-surgical probe which is amenable to separability of function, cleaning and storing characteristics, manufacturer, disposability of certain parts, compatibility with imaging techniques during application, faithful temperature monitoring for control of lesion size, safety against degradation, damage, and transmission of disease, and other important functional characteristics, usable for cool-tip or non-cooled RF or other electrodes or probes.
A further object of this continuation-in-part is to describe various embodiments of control systems together with computer or computer graphic workstation devices to practically control the process of thermal ablation, to preplan the ablation using image scan data, to monitor the progress of the ablation with computer graphics, to regulate those parameters to which the lesion or ablation volume is sensitive, to provide controls for automatic handling of the ablation procedure, and to provide the appropriate preplanning parameters and parameter and image characteristic monitoring to assure desired ablation volume. These are claimed for use with a cooled RF electrode for a standard non-cooled electrode.
Another objective of the present invention is to provide a closed distal tip cannula or catheter with an open lumen other end (proximal) which can act as an electrode, and in various embodiments may accept a stiff stylet, or an RF connection element, or a cooling element, or combinations of these, so that such a cannula will reduce the spread of disease or cancer in its application, so that it may be made to penetrate tissue that is closed to coolant perfusion and flow, so that it is separable from more expensive RF coolant and other elements, and so it can be supplied in varying degrees of exposed or heating tip configurations.
It is another object of the present invention to provide separable cannula or catheter, RF element, coolant elements, temperature-sensing element(s), stylets, etc. so that any combination of such elements may be used together or separately or in pairs. For instance, a cannula may be used with an RF connection element only if ablation is done just using RF generator parameters to do thermosurgery (for example without cooling the tip or without temperature monitoring of any kind). Or, the cannula or catheter may be used with an RF connector and cooling element, but no temperature monitoring is done, and the ablation is carried out based on, for instance, control of the RF power or current delivered to the electrode, and possibly the temperature of the coolant fluid supply.
A further object of the invention is to provide an integrated system of RF (or other power type) generator and coolant supply system which can be connected to a probe, electrode, cannula, or catheter to enable easy, safe, convenient, and visible integration of control of the thermosurgery by the operator. We claim, for instance, an integrated console or workstation of these elements to be cooperatively connected to a probe or multiple probes, serially or sequentially, or in parallel to achieve a desired ablation (lesion) volume.
Yet another objective of this invention is to provide a system of RF generator (or other heating generator) with a computer to control, monitor, or feed back parameters of the thermosurgery, or to preplan the ablation, or to map, fuse, or update images from one or more image scanners before, during, or after the thermosurgery or ablation process, alternatively in another embodiment to control, monitor, feed back a cooling supply and flow to a cooled electrode(s) or boundary controlling elements which will be illustrated in the Figures below.